Inventory of karstic cavities of the Schisto-Calcaire Group, Republic of the Congo: Applying a geoheritage promotion approach in the Madingou region

Karst systems are increasingly recognized as valuable geoheritage sites. Although Africa hosts numerous karst landscapes, few countries maintain comprehensive inventories. Here, we investigated the karstic cavities within the Schisto-Calcaire Group in the Republic of Congo and assessed their geoheritage potential. We identified 169 karstic cavities by compiling data from publications, speleological reports, and field expeditions mainly in the Bangou Forest, the Madingou and Loudima valley regions. The inventory shows that 42 cavities have archaeological or anthropological significance. The Madingou region was selected as a focal point for fieldwork due to its high concentration of karstic cavities. This led to the discovery of 24 new cavities and revealed advanced karst development, including cone karst morphologies (fengcong, fenglin), dolines, uvalas, and karst springs. These cavities host diverse speleothems, cave-dwelling fauna, and ceramic remains. The geomorphological features result from interactions between lithological variability, tectonic structures, and surface processes. The geoheritage potential was assessed using a six-criteria classification framework encompassing geomorphology, hydrology, endokarst, lithology-palaeontology, tectonics-structural, and archaeology. The results underscore the high scientific, touristic, and educational value of the Madingou karst, highlighting the need for geoconservation strategies and sustainable tourism development. This study marks the first implementation of a systematic inventory approach toward geoheritage promotion in a Congolese karstic region and in Central Africa. This approach offers a replicable model for other areas. Linking geoheritage to sustainable land management contributes to SDG 11.4 on safeguarding cultural and natural heritage, as well as SDG 4 (Quality Education), SDG 13 (Climate Action), and SDG 15 (Life on Land). • This new inventory documents 169 karstic cavities in the Schisto-Calcaire Group, Republic of Congo. • Most speleological investigations were conducted between 1950 and 1990. • Nkila Ntari is the longest cave identified, with a total development of 1500 m. • Inventoried karstic cavities are mainly concentrated in the Bangou Forest (Kindamba) and the Madingou and Loudima regions. • A six-type classification of karst features supports scientific geoheritage assessment. • This work promotes geoheritage and aligns with SDGs 4, 11.4, 13, and 15.